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PM83479: MIGRATING TO CICS4.2 YOU MAY EXPERIENCE CPU INCREASE IF APPLICATIONS ISSUE LARGE GETMAINS SPECIFYING INITIMG(X'0

A fix is available

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APAR status

  • Closed as program error.

Error description

  • You migrate from CICS 3.1 to CICS 4.2 and notice an increase
    in the amount of CPU used per task in the CICS 4.2 region
    compared to the CICS 3.1 region.   Looking at APA performance
    reports, we could see more CPU being used in module DFHSMMG.
    Upon further investigation we learned these applications do
    very large getmains specifying INITIMG(00).
    There was a change to this area of code in 4.2 where it does the
    initial image processing that appears to contribute to this
    increase in CPU.
    Additional Symptom(s) Search Keyword(s): KIXREVEPH
    

Local fix

  • contact ibm
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All CICS users.                              *
    ****************************************************************
    * PROBLEM DESCRIPTION: Increased CPU consumption performing    *
    *                      large GETMAINs.                         *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Large CICS GETMAINs with an INITIMG of zeros, consume an
    increased amount of CPU, when compared with earlier versions of
    CICS Transaction Server for z/OS.
    

Problem conclusion

  • The operations performed to initialise storage returned by a
    CICS GETMAIN with zeros, have been modified to improve
    performance.
    

Temporary fix

  •             *********
                * HIPER *
                *********
    FIX AVAILABLE BY PTF ONLY
    

Comments

APAR Information

  • APAR number

    PM83479

  • Reported component name

    CICS TS Z/OS V4

  • Reported component ID

    5655S9700

  • Reported release

    700

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2013-02-23

  • Closed date

    2013-04-26

  • Last modified date

    2013-06-04

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    PM86983 UK93832

Modules/Macros

  •    DFHSMMG
    

Fix information

  • Fixed component name

    CICS TS Z/OS V4

  • Fixed component ID

    5655S9700

Applicable component levels

  • R700 PSY UK93832

       UP13/05/02 P F305

Fix is available

  • Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

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Document Information

Modified date:
04 June 2013